SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20a3ea086feeab2fcd1410798f98c5bcce41a0cb6a832314a994f201d908fb63' 
  AND token = 'ZVF01rayBI+igcSfHN3CQzND6tLQJu4bN5GE9qrrypo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}